Nonabsorbable rabbit anti-Salmonella typhimurium antibody as detected by the complement-mediated bactericidal reaction.

Herzberg, Mendel (University of Florida, Gainesville), Kathryn V. Kenny, and John B. Robbins. Nonabsorbable rabbit anti-Salmonella typhimurium antibody as detected by the complement-mediated bactericidal reaction. J. Bacteriol. 91:1548-1555. 1966.-A portion of antibody active in the complement-mediated bactericidal reaction against Salmonella typhimurium from hyperimmune rabbit serum has been shown to be nonabsorbable by repeated serial absorptions with whole heat-killed or living bacteria. The first two absorptions remove 90 to 95% of the activity, but 1 to 5% cannot be removed by subsequent absorptions. The nonabsorbable antibody appears to be a macroglobulin by density-gradient centrifugation and by comparison of activity and absorbability of purified gamma-M and gamma-G immune globulins. Alternative hypotheses involving low avidity antibody or antibody to minor cell antigenic components are offered in explanation of the phenomenon.